Critical · 9.8 CVE-2026-68381 EUVD-2026-55567GHSA-gq9g-pv9h-2q5v

ksmbd: pin conn during async oplock break notification

Published Aug 10, 2026 · Updated Oct 30, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-6.12 Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-7.0 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-7.0 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.17 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fde-7.0 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-7.0 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.17 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-7.0 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-lowlatency Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-7.0 Package: linux-nvidia-bos Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oem-7.0 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-oracle-7.0 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.17 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-riscv-7.0 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: pin conn during async oplock break notification

smb2_oplock_break_noti() and smb2_lease_break_noti() store a ksmbd_conn
pointer in an async ksmbd_work and then queue that work on ksmbd-io. The
work only increments conn->r_count, which prevents teardown from passing
the pending-request wait after the increment, but it does not pin the
struct ksmbd_conn object.

If connection teardown races with an oplock break notification, the last
conn reference can be dropped before the queued worker finishes. The
worker then uses the freed conn in ksmbd_conn_write() and
ksmbd_conn_r_count_dec().

Take a real conn reference when publishing the conn pointer to the async
work item, and drop it after the notification work has decremented
r_count. Apply the same lifetime rule to lease break notification, which
uses the same work->conn pattern.

Affected products

Vendor	Product	Affected	Fixed
Linux	Linux	6.6.84 – < 6.6.148, 6.12.20 – < 6.12.101, 6.13.8 – < 6.14, 6.14	6.6.148

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Debian

Security tracker ↗

Release	Package	Fixed in	Advisory
Debian 14	linux	7.1.6-1	—
Debian 13	linux	6.12.101-1	—
Debian 12	linux-6.12	6.12.101-1~deb12u1	—

Ubuntu

Security tracker ↗

Release	Package	Fixed in	Advisory
Ubuntu Nvidia-BlueField 24.04 LTS	linux-bluefield	6.8.0-1033.38	—
Ubuntu 26.04 LTS	linux	7.0.0-38.38	USN-8887-1
Ubuntu 26.04 LTS	linux-aws +1	7.0.0-1014.14	USN-8887-1
Ubuntu 26.04 LTS	linux-azure	7.0.0-1017.17	USN-8888-1
Ubuntu 26.04 LTS	linux-azure-fde	7.0.0-1016.16	USN-8888-1
Ubuntu 26.04 LTS	linux-gke	7.0.0-1008.9	USN-8887-1
Ubuntu 26.04 LTS	linux-ibm +1	7.0.0-1015.15	USN-8889-1, USN-8887-1
Ubuntu 26.04 LTS	linux-nvidia	7.0.0-1025.26	USN-9043-1
Ubuntu 26.04 LTS	linux-nvidia-bos	7.0.0-2022.23	USN-9003-1
Ubuntu 26.04 LTS	linux-oracle	7.0.0-1013.13	USN-8887-1
Ubuntu 26.04 LTS	linux-raspi	7.0.0-1023.23	USN-9021-1
Ubuntu 26.04 LTS	linux-riscv +1	7.0.0-38.38.1	USN-8887-1
Ubuntu 24.04 LTS	linux	6.8.0-147.147	USN-8917-1
Ubuntu 24.04 LTS	linux-aws +1	6.8.0-1067.70	USN-9024-1, USN-8917-1
Ubuntu 24.04 LTS	linux-aws-7.0 +1	7.0.0-1014.14~24.04.1	USN-8887-3, USN-8887-2
Ubuntu 24.04 LTS	linux-azure-7.0	7.0.0-1017.17~24.04.1	USN-8888-2
Ubuntu 24.04 LTS	linux-azure-fde	6.8.0-1069.76	USN-8918-1
Ubuntu 24.04 LTS	linux-azure-fde-7.0	7.0.0-1016.16~24.04.1	USN-8888-2
Ubuntu 24.04 LTS	linux-gcp +1	6.8.0-1071.79	USN-8918-1, USN-8917-1
Ubuntu 24.04 LTS	linux-gke	6.8.0-1066.74	USN-8917-1
Ubuntu 24.04 LTS	linux-gkeop	6.8.0-1052.56	USN-8917-1
Ubuntu 24.04 LTS	linux-hwe-7.0	7.0.0-38.38~24.04.4	USN-8887-3
Ubuntu 24.04 LTS	linux-ibm	6.8.0-1067.68	USN-8917-1
Ubuntu 24.04 LTS	linux-lowlatency	6.8.0-147.147.1	USN-8917-1
Ubuntu 24.04 LTS	linux-nvidia-7.0	7.0.0-1024.25~24.04.1	USN-9003-1
Ubuntu 24.04 LTS	linux-nvidia-lowlatency	6.8.0-1067.70.1	USN-9040-1
Ubuntu 24.04 LTS	linux-nvidia-tegra	6.8.0-1035.38	USN-8781-1
Ubuntu 24.04 LTS	linux-oracle	6.8.0-1064.67	USN-8917-1
Ubuntu 24.04 LTS	linux-oracle-7.0	7.0.0-1013.13~24.04.1	USN-8887-3
Ubuntu 24.04 LTS	linux-raspi	6.8.0-1068.72	USN-9025-1
Ubuntu 24.04 LTS	linux-riscv +29	No fix yet	—
Ubuntu 24.04 LTS	linux-riscv-7.0	7.0.0-38.38.1~24.04.1	—
Ubuntu 24.04 LTS	linux-vmware	6.8.0-1008.8	—
Ubuntu 22.04 LTS	linux-aws-6.8	6.8.0-1069.74~22.04.1	USN-9024-1
Ubuntu 22.04 LTS	linux-azure-6.8	6.8.0-1073.82~22.04.1	USN-9026-1
Ubuntu 22.04 LTS	linux-azure-fde-6.8	6.8.0-1071.78~22.04.1	USN-9026-1
Ubuntu 22.04 LTS	linux-gcp-6.8	6.8.0-1073.81~22.04.1	USN-9024-1
Ubuntu 22.04 LTS	linux-hwe-6.8	6.8.0-149.149~22.04.1	USN-9066-1
Ubuntu 22.04 LTS	linux-ibm-6.8	6.8.0-1069.70~22.04.1	USN-9024-1
Ubuntu 22.04 LTS	linux-lowlatency-hwe-6.8	6.8.0-149.149.1~22.04.1	USN-9024-1
Ubuntu 22.04 LTS	linux-oracle-6.8	6.8.0-1067.71~22.04.1	USN-9025-1
Ubuntu 22.04 LTS	linux-riscv +33	No fix yet	—
Ubuntu 20.04 LTS	linux-gke +28	No fix yet	—

Show 5 more (older releases, extended support, other products)

Release	Package	Fixed in	Advisory
Ubuntu 18.04 LTS	linux-gcp +14	No fix yet	—
Ubuntu 16.04 LTS	linux-hwe-edge	No fix yet	—
Ubuntu Pro Realtime 24.04 LTS	linux-raspi-realtime	6.8.0-2056.58	USN-9025-1
Ubuntu Pro Realtime 24.04 LTS	linux-realtime	6.8.1-1062.63	USN-8917-1
Ubuntu Pro Realtime 24.04 LTS	linux-realtime-6.14 +1	No fix yet	—
Ubuntu Pro Realtime 22.04 LTS	linux-realtime-6.8	6.8.1-1064.65~22.04.1	USN-9024-1
Ubuntu Pro FIPS-updates 24.04 LTS	linux-aws-fips	6.8.0-1067.70+fips1	USN-8917-1
Ubuntu Pro FIPS-updates 24.04 LTS	linux-fips	6.8.0-147.147+fips1	USN-8917-1
Ubuntu Pro FIPS-updates 24.04 LTS	linux-gcp-fips +1	6.8.0-1071.79+fips1	USN-8918-1, USN-8917-1

Advisories 18

USN-9066-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9021-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9024-1 linux-aws-6.8, linux-gcp-6.8, linux-ibm-6.8, linux-lowlatency-hwe-6.8, linux-nvidia, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9026-1 linux-azure-6.8, linux-azure-fde-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
WID-SEC-2026-2730 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
USN-9040-1 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9043-1 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8917-1 linux, linux-aws, linux-aws-fips, linux-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-ibm, linux-lowlatency, linux-oracle, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9025-1 linux-oracle-6.8, linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8887-1 linux, linux-aws, linux-gcp, linux-gke, linux-ibm, linux-oracle, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9003-1 linux-nvidia-7.0, linux-nvidia-bos vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8887-3 linux-gcp-7.0, linux-hwe-7.0, linux-oracle-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8888-2 linux-azure-7.0, linux-azure-fde-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8918-1 linux-azure, linux-azure-fde, linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8888-1 linux-azure, linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8887-2 linux-aws-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8889-1 linux-oem-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8781-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026

References